Effect of hydrogen peroxide on improving the heat stability of whey protein isolate solutions.

Whey protein isolate (WPI) solutions (12.8%w/w protein) were treated with varying concentrations of H2 O2 in the range of 0-0.144 H2 O2 to protein ratios (HTPR) by the addition of the required quantity of H2 O2 and deionized water. The samples were analyzed for heat stability, rheological properties, denaturation level of β-lactoglobulin (β-LG) and α-lactalbumin (α-LA). The samples treated with H2 O2 concentration >0.072 (HTPR) showed significant improvement in the heat stability, and decreased whey protein denaturation and aggregation. The WPI solution treated with H2 O2 (>0.072 HTPR) remained in the liquid state after heat treatment at 120°C, whereas the control samples formed gel upon heat treatment. Detailed analysis of these samples suggested that the improvement in the heat stability of H2 O2 treated WPI solution was attributed to the significant reduction in the sulfhydryl-disulfide interchange reaction during denaturation of β-LG and α-LA.